It means that when pruning fruit trees, the south keeps them for fear that the branches in the south will affect the north, and the north keeps them. Generally speaking, the lighting effect in the north is not good, so this pruning is chosen. Similarly, "the east is high and the west is low" because the sun and temperature are strongest from 12 to 15 after noon, so don't be blocked by high branches to the west.

And all this is based on the law that the sun is south and the sun is west at noon. In general, it is to let the branches and leaves on the tree see the sun. After all, everything grows by the sun.

Extended data:

"The top is sparse and the bottom is dense, the outside is sparse and the inside is dense, and the big branches are sparse and the small branches are dense." This is because with the growth of tree age, the branches and leaves inside the fruit tree can not get enough sunshine tending and photosynthesis, so the outside of the fruit tree must be sparse and dense. These formulas are basically based on the ventilation, symptoms and light of fruit trees.

For this dogmatic pruning, different pruning methods should be adopted according to different places, different tree potentials, row spacing, plant spacing, growth potential, density and water and fertilizer conditions of tree age! You can't stick to it, you should cut it according to the actual tree.

Pruning is an important measure in fruit tree cultivation technology, which helps to improve the light conditions of fruit trees, adjust nutrient distribution, expand the crown and maintain a good tree structure, thus achieving the purpose of high quality, high yield and stable yield.